Study On Testing Method And Fatigue Reliability Analysis Of Driving Axle

Reliability of driving axle influences the reliability of vehicle directly. During vehicle running, the road conditions are variable, especially when vehicle runs on rough road, appended dynamic load caused by vehicle vibration and impact of collision caused by rough road make driving axle's loads to become complex. The driving axle's working condition is rough. House of driving axel, main reducing gear etc. must work reliably in the specified effective life until the vehicle is scraped.Currently safety factor method is adopted in the design of driving axle. The method can not solve coordination between light weight and strength requirement. So variable methods being used in design and manufacture to analyze reliability and forecast life period will be indispensability in reliability design of driving axle.Precision of Reliability and life analysis is restricted because of many infection factors. Problems of design can not be solved completely. So not only the main components of driving axle will be tested on life testing bench, but also the whole driving axle's reliability must be checked..The author develops roll wheel projection driving axle fatigue reliability test-bed. The test-bed can test the whole driving axle.In chapter 2, according to the fatigue property and fatigue damage accumulation of material and component, the dissertation analyses the proceeding of component's fatigue life prediction, and gives an engineering method of fatigue life prediction using fatigue damage accumulation theory. The method can be used in varying load properties. The dissertation also deduces the stress life model and the strain life prediction model which can be used to equiamplitude loading, variable amplitude loading and random loading.In chapter 3, the dissertation analyses the components of driving axle's reliability solving method using stress-strength interference model and dynamic stress-strength interference model under equiamplitude loading, variable amplitude loading and random loading.In chapter 4, the dissertation gives the design idea of roll wheel projection driving axle fatigue reliability test-bed. The dissertation also introduces optimum combination of motion inertia simulation and optimal confirmation of running resistance simulation, and the test system's kinematics model and it's feature.In chapter 5, according to road property, the dissertation discusses the principle of simulation road in time domain constructed by frequency domain, the emphasis on simulating limitless road by use of limited roll wheel's surface of test-bed and theory of simulating rough road by use of projection. Based on the theory, the dissertation constructs variable rank road surface of two traffic lane. According to analyzing the road surface's feature, using a group of projections to reappear testing field's road surface on the test-bed is proved to be reasonable.In chapter 6, the dissertation introduces the principle of drive axle fatigue reliability fast test and discusses the method and process of data acquisition. The author measured load spectrum of ZL-50 driving axle and stress spectrum of house leaf spring seat and analyzed stress spectrum of driving axle house on the test field. By these works, the author proves the drive axle bench test's fast fatigue testing is similar to road test. According to drive axle house's fatigue life prediction of simulation test and road test's load spectrum, the author discusses the equivalent relationship between simulation test and road test.Finally, the author summarizes the research and prospects the future's work, presents some suggestions.